is there any resources on the net about presentation can someone help???

You've found the best resource on the net!

Everyone here has given you really good advice, but I want to ad another 2¢-worth.

Putting together a portfolio is--at it core--no different than designing any sales piece (be it ad, brochure, or billboard). There are two questions you have to answer before you assemble the portfolio:

Who am I talking to?

What do I want to communicate?

This means you need to do some research on the place/person with whom you are going to interview and the position they are seeking to fill. Are they looking for a designer to do conceptual work, a designer who can do production, a production artist who can do some design, or a production person with no design aspirations? Do they work quick and clean, or quicker and dirty (in theory, they could work slow and clean, but nobody does)? Do they do mostly 1-, 2-, or 4-color? What kinds of projects do the do?

Now, out of your body of work, pick 4 to 10 pieces that are most-appropriate to this job, and that becomes your portfolio this time.

4 great pieces are better than 4 great ones and 6 crappy ones

Don't bring everything you've ever worked on

Don't include anything you feel the need to appologize for

Be prepared to tell the interviewer why what you did on each piece is relevant to the job you wish to get

Remember, the person who is interviewing you is short-handed, and has other pressing things to do

Repeat for the next job interview. Now, this process is easier if all of the stuff is mounted similarly. It doesn't really matter if its on boards, in plastic sleeves or something else--as long as its neat and easily re-arranged.